Projecting lamp



June 20, 1933. G, H. cusHlNG Cltkoz una Patented y June 20, 1933 UNITEDv STATES.

PATENT oi-Fics GEORGE H. CUSHING, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO CUSHING LAMP INCORPORATED, 0F WASHINGTON, DISTRICT OF COLUMBIA, A CORPORATION OF DELAWARE .Application led March 13, 1929,Serial No.

This invention relates in generalto illumination and more particularly has reference to projecting lamps and reflectors associated therewith.

It is well known that light from a source emanates with the same degree of intensity in all directions. Reflectors have long been used in the illuminating art for redirecting the light rays emanating from a source in a desired direction and illuminating particular objects. These reflectors have been constructed of various materials and formed into various shapes and sizes. The present practice, particularly in the automotive industry, is to provide reflectors for projecting lamps used on automobiles, which are formed of a polished metal. These metallic reflectors are usually formed by stamping on spinning a brass-like metal into various shapes. After the reflectors are shaped and the reflecting surface finished, thelatter surface is usually plated with a lustrous metal such as silver, nickel, or other similar metals.

Light projected or redirected from a reflecting surface, formed as just described, is in many instances glaring, or dazzling. A beam projected from these reflectors is generally somewhat distorted. A portion of the glaring effect is in general due to the high reflective power-of the lustrous metal coated onto the base metal forming the reflector. The unevenness in the beam and the glaring effect are .generally caused by imperfections in the reflecting surface of the finished reflector. Imperfections in the reflecting surface cannot be yeasily removed, particularly if the reflectors are produced in large quantities, such as by stamping or spinning, unless a relatively costly procedure is involved. The metal usually employed for plating the base metal of the reflectors does not have the proper flow characteristics to lill up the voids in the reflecting surface of the metallic reflector, and, consequently,

the imperfections are still apparent after l plating.

An object of thisinvention to provide ya metallic'reiector for projecting the rays of light Yemanating from a light source,

PROJECTING LAMP 346,690. Renewed November 14, 1932.

which lacks the disadvantages inherent in the reflectors heretofore produced.

Another object of this invention is to provide a reflecting surface which imparts a 'vise a method of forming reflecting surfaces to produce reflectors having desirable light reflecting characteristics. Still another object vf this invention is to devise a method of treating'the base metal of a reflector to fill in any imperfections in the reflecting surface.

With these 'and other objects in view, which may be incident to my improvements, the invention consists in the product-s and methods of preparation to be hereinafter set that the several necessary features of my invention may be varied as desired without departing from the spirit and scope of the appended claims.

This invention is based upon the concept of plating a reflecting surface first with a metal such as gold, which will fill in substantially all reflecting surface, and then subsequently plating the gold plated reflector with a lustrous metal such as silver to impart high light reflecting characteristics to the reflector.

forth and claimed, with the understanding of the imperfections in the In order to make my invention more clearly understood, I have shown in the accompanying drawing means for carrying the same into practical effect, without limiting the` improvements in their useful application tothe particular constructions, which for the purpose of explanation, have been made the subject of illustration.

In the drawing:

Figure 1 is a somewhat diagrammatic sectional view of a projecting lamp having reflecting surfaces constructed in accordance with the present invention.

Figure 2 is a magnified sectional view taken on line 2 2 of Figure 1.

Figure 3 is a magnified sectional view taken on line 3 3 of Figure 1.

Refcrringto the drawing, in which similar reference numerals indicate similar parts, there is shown in Figure 1 a projecting lamp having reflecting surfaces constructed in accordance-with this invention. The lamp shown in Figure 1 is of the type employing secondary reection. This lamp comprises a primary reflector 1, relatively to which is suitably positioned a light source in the form of an electric bulb 2. The bulb is provided with a base 3, which is received in a suitable receptacle 4 attached to the primary reflector 1. Associated with the primary reflector is a secondary reflector 5, which is adapted to receive light rays projected by the primary reflector and to redirect these rays at substantially right angles to the rays emanated from the primary reflector. A lens 6 of any desired type may be affixed to the forward portion of the projecting lamp to protect the element-s of the lamp structure from exposure lto the Weather.

Refl'ectors 1 and 5 may either or both be constructed in accordance with the present invention. In Figures 2 and 3 a magnified -section of the reflecting surfaces, constructed in accordance With this invention, is shown. These reflecting surfaces comprise a reflector formed of a base met-al 7, such as any desired form of brass, and plated on the base ,metal is a layer of gold, indicated b reference numeral 8. The coating of go d tends to fill in any imperfections in the surface of the brass-like base 7 and thereby provide a substantially perfect reflecting surface. In order to increase the whiteness of the light reflected from the reflector-a layer 9 of silver is deposited over the layer of gold. The substantially perfect surface of the reflector, due to the plate of gold, provides a finished reflector having a surface which will redirect rays of light falling thereon in a manner determined by the construction of the reflector. The combination of the silver plated reflector with the intermediate layer of gold has been found to be very eflicient for softening the light reflected from the surface thereof. Light reflected from a lreflector constructed as hereinbefore pointed out has characteristics similar to those of daylight; for instance, the light projected from the reflector constructed in accordance with this invention may be used to match colors and for examining all textile materials.

The peculiar properties of light reflected from the surfaces of the reflectors is due, in part, to the spectral characteristics of the combination of the yellow-like gold and the `White metal deposited thereover.

In addition to the effect produced by the,

combination of the different spectral characteristics of the two metallic layers the base -metal is afforded greater electro-chemical protection by the adjacent layer of gold, which is very resistive to corrosion.

The secondary reflector, a portion of which is shown in Figure 3, is constructed in practically the samey manner as the primary reflector shown in Figure 2; that is, the body of the reflector consists of a brass like base metal on which is plated a layer of gold, and over the gold layer is plated a layer of silver.

In carrying out Imy invention the several layers of metal may be placed on the foundation metal in any desired manner. It has been found that several layers can be advantageously placed over the base metal by clectroplating.

The reflectors are stamped or otherwise formed into the desired shapes from base metal, such as any of the brasses used for such purposes. The base metal objects, such as the brass-like stampings or structure are treated by bufling, pickling to remove oxides, immersion in suitable solvents to remove grease, or by electrolytic cleaning. If desired, the base metal may be degasified prigr to being introduced into the plating The object to be plated may be immersed in any of the usual electrolytic baths. Actual conditions of the plating operations such as the composition, concentration and temperature of the electrolyte, current density and shape of the anode may be varied to secure the desired results. By properly controlling the conditions such as the current density, the crystalline structure of the plates can be formed as desired. a

In arranging the several layers of meta on the brass-like foundation or base metal by electroplating, the reflecting surface 1s first subjected to a gold plating process and later to a silver plating process. After the reflector is finished, the reflecting surface may be treated in 4any manner to provide and preserve a lustrous finish.

While in the foregoing description I have referred specifically to gold and silver as the metals for plating the foundation metal of the reflectors, I wish it to be clearly understood that other metals having desirable characteristics similar to gold and silver may be substituted for the gold and silver used.

While I have` shown and described the 4preferred embodiment of my invention, I

Wish it to be understood that I do not confine myself to the precise elements, method steps and details of construction herein set forth, by way of illustration, as it is apparv ent that many changes and variations may be made therein, by those skilled in the art,

2. A light reflector comprising a brassn like foundation metal, a layer of yellowlike metal deposited thereon and an outer layer of White metal, said outer layer being sufficiently thin to-permit the reeeted light from the combination of the yellowlike and white metals to resemble day light.

3. A light reflector comprising a brasslike foundation metal, a layer of gold deposited thereon and an outer layer of White metal, said outer layer being sufficiently thin` to permit the reflected light fromthe combination of the gold and white metals to resemble day light.

4c. A light reflector comprising a brasslike foundation metal, a llayer of gold def. posited thereon and an outer layer of silver, said outer layer being suici'ently thin to permit the reflected light from the combination of the gold and silver to resemble day light.

GERGE H. CUSHING.

lin testimony whereof l affix my signature. 

